A synchronous dynamic random access memory (SDRAM), which is a type of memory, may be used in various types of computing devices, and may be accessed by various types of processors. A memory controller may generate a signal for controlling a read/write operation of a memory, in response to a command and an address given by a processor. In the case of the SDRAM, a row in which a memory cell is located must generally be activated before the memory cell may be accessed. One of the operations of the memory controller may be to determine whether a row that is to be accessed is activated. If the row that is to be accessed is not activated, the memory controller may activate the row before performing the read/write operation in the row. Another operation of the memory controller may be to deactivate a previously accessed row when a new row is accessed.
Also, the SDRAM may perform a precharge operation after performing the read/write operation. If the precharge operation is performed, an activated row may be deactivated and a voltage of a column may be set as a precharge voltage. The precharge operation may need an additional clock cycle. If the same row of the same memory bank (“bank”) is continuously accessed, it may be better for the SDRAM not to perform the precharge operation. If one row and then another row are sequentially accessed in the SDRAM, the precharge operation must generally be performed. However, a conventional memory controller may not control the precharge operation to be performed according to whether the same row in the same bank is repeatedly accessed. That is, the conventional memory controller may apply either an auto precharge mode or an open page mode to all banks of an SDRAM. The auto precharge mode may be a mode in which a memory automatically performs the precharge operation after performing the read/write operation. The open page mode may be a mode in which an activated row remains activated until a precharge command is given from the memory controller. If one row and then another row are sequentially accessed in a bank, the auto precharge mode may be preferable, and if the same row is repeatedly accessed in the same bank, the open page mode may be preferable. However, conventionally, only one of the auto precharge mode and the open page mode may be applied to all banks of the memory as described above, thereby increasing unnecessary consumption of power and time.